Various forms of solid state imaging, memory and energy conversion systems are known and used in the art with varying degrees of economy, efficiency and ease of manufactures, there being tradeoffs between each of these desirable goals. One form of energy conversion uses the thermodielectric effect to convert infrared radiation to electrical energy, as is disclosed in Hoh U.S. Pat. Nos. 3,073,974 and 3,243,687, incorporated herein by reference. The materials disclosed in the Hoh patents are in the class of ferroelectric energy converters which are very temperature dependent in the neighborhood of the ferroelectric Curie point so these materials can be used as thermal detectors in solid state infrared detectors and imaging systems. The metal-insulator-semiconductor (MIS) art is now well developed and infrared imaging systems using inversion mode operated MIS devices with charge coupled devices (CCD), wherein an inversion region or layer is created at the insulator-semiconductor interface into which photogenerated minority are collected are known, see the article by Andrew J. Steckl et al entitled "Application of Charge Coupled Devices to Infrared Detection and Imaging", published in the IEE publication "Charge Coupled Devices: Technology and Applications" copyrighted in 1977, and incorporated herein by reference.
The objects of the present invention include providing improved radient energy sensing systems, large scale electrical memories and imaging methods and apparatus. In achieving these objects, the present invention, in one preferred mode, utilizes a very thin ferroelectric material as the insulator of a MIS device. In another aspect of the invention, a very thin, low heat capacity ferroelectric material having thermodielectric properties is combined with a charge coupled device and serves as the retina of an infrared imaging device, and the charge coupled device can be a part of a MIS device. In still another and preferred aspect of the invention infrared energy is converted to electrical energy in a thin ferroelectric layer having thermodielectric properties, the thin ferroelectric layer constituting the insulator in a MIS device, the voltage produced by the thermodielectric conversion in the ferroelectric layer operates to create an inversion region or layer in the semiconductor body and a virtual PN junction. In such state, the utilization of the charge storage and transfer ability of an electroded polarized insulator (e.g. a ferroelectric body member having dipole structure) and semiconductor interface permits data to be stored and the device used as a large scale electronic memory.